Franz-Erich Wolter is a German computer scientist, chaired professor at

Leibniz University Hannover Gottfried Wilhelm Leibniz University Hannover (german: Gottfried Wilhelm Leibniz Universität), also known as the University of Hannover, is a public research university located in Hanover, Germany. Founded on 2 May 1831 as Higher Vocational Sc ...

, with research contributions especially in computational (differential) geometry and haptic/tactile Virtual reality. He currently heads the Institute of Man-Machine Communication and is the Dean of Studies in Computer Science at Leibniz University Hannover. He is the founder and actual director of the Welfenlab research laboratory.

Research

Wolter's early contributions were in the area of Differential Geometry dealing with the

Cut Locus The cut locus is a mathematical structure defined for a closed set S in a space X as the closure of the set of all points p\in X that have two or more distinct shortest paths in X from S to p. Definition in a special case Let X be a metric s ...

characterizing it as the closure of a set, where the shortest

geodesic In geometry, a geodesic () is a curve representing in some sense the shortest path ( arc) between two points in a surface, or more generally in a Riemannian manifold. The term also has meaning in any differentiable manifold with a connection. ...

s starting from a point (or a general source) set intersect or equivalently where the distance function is not directionally differentiable implying that a complete Riemannian manifold M must be diffeomorphic to R^n if there is a point p on M s.t. the (squared) distance function wrt. to p is (directionally) differentiable on all M. His Ph.D. thesis (1985) transferred the concept of Cut Locus to manifolds with and without boundary. In 1992, essentially a specialisation of the latter works lead to his paper presenting a mathematical foundation of the

medial axis The medial axis of an object is the set of all points having more than one closest point on the object's boundary. Originally referred to as the topological skeleton, it was introduced in 1967 by Harry Blum as a tool for biological shape recogn ...

of solid objects in Euclidean space. It showed that the medial axis of a solid body can be viewed as the interior Cut Locus of the solid`s boundary and the medial axis is a

deformation retract In topology, a branch of mathematics, a retraction is a continuous mapping from a topological space into a subspace that preserves the position of all points in that subspace. The subspace is then called a retract of the original space. A deforma ...

of the solid. Therefore it represents the homotopy type of a solid thus including the solid's homology type. Furthermore the medial axis can be used to reconstruct the solid. Later on since 1997 the subject of the medial axis received a rapidly growing attention in computational geometry but also wrt. its applications in vision and robotics. A

Voronoi diagram In mathematics, a Voronoi diagram is a partition of a plane into regions close to each of a given set of objects. In the simplest case, these objects are just finitely many points in the plane (called seeds, sites, or generators). For each seed th ...

of a finite point set A in Euclidean space can be viewed as Cut Locus of that point set. In 1997, Wolter apparently pioneered computations of geodesic Voronoi diagrams and geodesic medial axis on general parametrized curved surfaces. In the surface case the length of a shortest geodesic join defines the distance between two points. In 2007, Wolter extended the computations of geodesic Voronoi diagrams and geodesic medial axis (inverse) transform to Riemannian 3D-manifolds. Wolter's early works on computing Riemannian Laplace Beltrami spectra for surfaces and images lead to a patent application in (2005) for a method using those spectra as Shape DNA for recognizing and retrieving surfaces, solids and images from data repositories. His works used the heat trace of a Riemannian Laplace Beltrami operator wrt. a surface patch to numerically compute area, length of boundary curves and Euler Characteristic of the patch. All this later on stimulated research in the area of

spectral shape analysis Spectral shape analysis relies on the spectrum (eigenvalues and/or eigenfunctions) of the Laplace–Beltrami operator to compare and analyze geometric shapes. Since the spectrum of the Laplace–Beltrami operator is invariant under isometries, it ...

wrt. shape retrieval and shape analysis, including applications in biomedical shape cognition and especially using the heat kernel more precisely the heat trace for partial shape cognition and the global point signature. Wolter was responsible for creating model and software for the haptic/tactile renderer of the visuo-haptic-tactile Virtual Reality (VR) system HAPTEX – HAPtic sensing of virtual TEXtiles, developed as multinational EU-project (2004-2007). (Haptic and tactile perception are considered as different with tactile referring to perception obtained via mechano receptors in the skin from lightly touching a surface while haptic perception caused by more forceful mechanical interaction with an object perhaps deforming it). HAPTEX appears to be the only VR-System allowing simultaneously a combined haptic and tactile perception of multi point haptic interaction with computer generated deformable objects, c.f. Under Wolter's guidance research on the haptic and tactile renderer of HAPTEX resulted in two doctoral theses of his students published as monographies by Springer, cf. More recently Wolter's works have covered research on volumetric biomedical visualization systems, (YaDIV), and haptic tactile VR-Systems currently including haptic interaction with medical volumetrically presented MRI and CT data.

Biography

Prof. Wolter received a Diploma in Mathematics and Theoretical Physics from the

Free University of Berlin The Free University of Berlin (, often abbreviated as FU Berlin or simply FU) is a public research university in Berlin, Germany. It is consistently ranked among Germany's best universities, with particular strengths in political science and t ...

and a Ph.D. (1985) in Mathematics from the

Berlin Institute of Technology The Technical University of Berlin (official name both in English and german: link=no, Technische Universität Berlin, also known as TU Berlin and Berlin Institute of Technology) is a public research university located in Berlin, Germany. It was ...

. After his Ph.D., before switching to an academic career, he had been working as software and development engineer in the electrical industry for

AEG Allgemeine Elektricitäts-Gesellschaft AG (AEG; ) was a German producer of electrical equipment founded in Berlin as the ''Deutsche Edison-Gesellschaft für angewandte Elektricität'' in 1883 by Emil Rathenau. During the Second World War, AEG ...

. Prior to coming to Hannover, he held faculty positions at the University of Hamburg (Germany), at MIT (USA) and at Purdue University (USA). Early on and throughout his career, Wolter hold for extended periods various positions as a visiting professor at well known schools including especially MIT (three times), Nanyang Technical University, Purdue University. He has been presenting seminars at many prestigious Universities including: Harvard, Yale, Stanford, Brown University, MIT and more recently in Asia: Tsinghua University, Zheiyang University, and Nanyang Technical University. He gave Keynote Speeches at CGI 2000 and CGI 2010, covering major parts described in the above research section. Wolter is an associate editor of the Springer Journal "The Visual Computer". He had been General Chair of the international conferences:

Computer Graphics International Computer Graphics International (CGI) is one of the oldest annual international conferences on computer graphics. It is organized by the Computer Graphics Society ''The'' () is a grammatical Article (grammar), article in English language, Eng ...

1998, Cyberworlds and NASAGEM 2007,

2013.

Awards and honors

Wolter's article on the computation of geodesic Voronoi diagrams on parametric surfaces received the best paper award of CGI 1997. His paper on "Laplace Beltrami Spectra as Shape DNA" received the most cited paper award of the CAD journal in 2009. His joint paper with partners of the EU funded Haptex project received the best applied paper award of JVR - journal.

References

{{DEFAULTSORT:Wolter, Franz-Erich Year of birth missing (living people) Living people German computer scientists Academic staff of the University of Hanover Free University of Berlin alumni Technical University of Berlin alumni Academic staff of the University of Hamburg